4 * This file is part of LyX, the document processor.
5 * Licence details can be found in the file COPYING.
7 * \author Alejandro Aguilar Sierra
8 * \author Lars Gullik Bjønnes
10 * Full author contact details are available in file CREDITS.
13 // Generalized simple lexical analizer.
14 // It can be used for simple syntax parsers, like lyxrc,
15 // texclass and others to come.
20 #include "support/strfwd.h"
27 namespace support { class FileName; }
37 /** Generalized simple lexical analizer.
38 Use the method isOK() to check if there is still data available
39 for lexing. Use one of the the operators void* or ! to test if
40 the last reading operation was successful.
44 int readParam(LyxLex &lex) {
45 int param = 1; // default value
46 if (lex.isOK()) { // the lexer has data to read
47 int p; // temporary variable
49 if (lex) param = p; // only use the input if reading was successful
54 @see LyXRC.cpp for an example of usage.
59 Lexer(keyword_item *, int);
75 /// stream is open and end of stream is not reached
76 /// FIXME: test also if pushTok is not empty
77 /// FIXME: the method should be renamed to something like
78 /// dataAvailable(), in order to reflect the real behavior
80 /// FIXME: The next two operators should be replaced by one method
81 /// called e.g. lastReadOk(), in order to reflect the real
83 /// last read operation was successful.
84 operator void const *() const;
85 /// last read operation was not successful
86 bool operator!() const;
87 /// return true if able to open file, else false
88 bool setFile(support::FileName const & filename);
90 void setStream(std::istream & is);
92 std::istream & getStream();
93 /// Danger! Don't use it unless you know what you are doing.
94 void setLineNo(int l);
95 /// Change the character that begins a comment. Default is '#'
96 void setCommentChar(char c);
98 /// returns a lex code
101 /** Just read the next word. If esc is true remember that
102 some chars might be escaped: "\ atleast
104 bool next(bool esc = false);
106 /** Read next token. This one is almost the same as next,
107 but it will consider " as a regular character and always
108 split a word if it contains a backslash.
111 /// Push a token, that next token got from lyxlex.
112 void pushToken(std::string const &);
115 int getLineNo() const;
118 int getInteger() const;
120 bool getBool() const;
122 double getFloat() const;
124 std::string const getString() const;
127 docstring const getDocString() const;
129 /** Get a long string, ended by the tag `endtag'.
130 This string can span several lines. The first line
131 serves as a template for how many spaces the lines
132 are indented. This much white space is skipped from
133 each following line. This mechanism does not work
134 perfectly if you use tabs.
136 std::string const getLongString(std::string const & endtag);
141 /// Pushes a token list on a stack and replaces it with a new one.
142 void pushTable(keyword_item *, int);
144 /** Pops a token list into void and replaces it with the one now
149 /** Prints an error message with the corresponding line number
150 and file name. If message contains the substring `$$Token',
151 it is replaced with the value of GetString()
153 void printError(std::string const & message) const;
155 /// Prints the current token table on the supplied ostream.
156 void printTable(std::ostream &);
159 Lexer & operator>>(std::string &);
160 /// extract docstring
161 Lexer & operator>>(docstring &);
163 Lexer & operator>>(double &);
165 Lexer & operator>>(int &);
166 /// extract unsigned integer
167 Lexer & operator>>(unsigned int &);
169 Lexer & operator>>(bool &);
171 /// Quotes a string so that reading it again with Lexer::next(true)
172 /// gets the original string
173 static std::string const quoteString(std::string const &);
177 Lexer(Lexer const &);
178 void operator=(Lexer const &);
185 mutable bool lastReadOk_;
189 /** Use to enable multiple exit points.
190 This is needed to ensure that the pop is done upon exit from methods
191 with more than one exit point or that can return as a response to
195 class PushPopHelper {
198 PushPopHelper(Lexer & lexrc, keyword_item * i, int s) : lex(lexrc) {
208 /** Avoid wrong usage of PushPopHelper.
209 To avoid wrong usage:
210 PushPopHelper(...); // wrong
211 PushPopHelper pph(...); // right
213 #define PushPopHelper(x, y, z) unnamed_PushPopHelper;
214 // Tip gotten from Bobby Schmidt's column in C/C++ Users Journal